From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54C92606A330 for ; Sat, 14 Nov 2026 22:38:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gnu.org header.i=@gnu.org header.a=rsa-sha256 header.s=fencepost-gnu-org header.b=ble8xtey Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xSMN8-0005L8-DQ; Sat, 14 Nov 2026 17:37:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xSMN6-0005Ks-5M for qemu-devel@nongnu.org; Sat, 14 Nov 2026 17:37:20 -0500 Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xSMN4-0000Jt-Nj; Sat, 14 Nov 2026 17:37:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=In-Reply-To:MIME-Version:References:Subject:To:From: Date; bh=a4Dqt6GDj7BUTxNijNnpJKJab28aWBoYzolKj9C5ido=; b=ble8xteyY62ofZ6h0Dda 5MyDEk7D3AN4KyQn5qq8BEIOfHcA6Il//RTq872FrBZknbk0FE45WmauN0DSD/6OTdvii1hKaW532 3gAKviDKJpekPeyQGQXxE/hAozn5v/kFhbO0t7R61utUxI8rJLokq0RRSbwcEKQN2hbYwhRNYGxTp f4bMc3BuXvG+3Lsx4DLhucybDHfGtHcocoDo3Dx9KtuOJWVuje6Y8aoZ6bS9RhLcC8HDDUTPDRmkn OgHrVZsjX0RV1EHbd4a1PPFQQ1DrtunUfT0+eLQhVoO0jBqYJzILbigelj6mI8ex98603UQVrkIaV VPZLoz27RANHvg==; Date: Sat, 14 Nov 2026 23:37:15 +0100 From: Samuel Thibault To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Gavin Li , qemu-devel@nongnu.org, Paolo Bonzini , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , Pierrick Bouvier , Jason Wang Subject: Re: [PATCH v1] net: add per-connection guestfwd unix support Message-ID: References: <20261107044225.2786-1-gavin.li@samsara.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: I am not organized X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hello, Daniel P. Berrangé, le jeu. 12 nov. 2026 15:21:20 +0000, a ecrit: > On Fri, Nov 06, 2026 at 11:42:25PM -0500, Gavin Li wrote: > > For -netdev user,guestfwd=..., add support for unix-per-connection: in > > addition to the currently supported tcp: and cmd:. With > > unix-per-connection:, a new connection is opened to the given unix > > socket. This is an improvement over the current unix: support, which > > does not support 1:1 guest:host connections. > > I'm not familiar with guestfwd, but from the manpage, I would > rather assume that it always opens a new connection to the host > socket for each guest connection. No, qemu opens the unix socket at initialization and just forwards data to it. > What are its current semantics when two guest connections are > initiated on the same port, if that's not happening ? It's just mixing the data coming from the connections into the unix connection, and sending all data from the unix connection to one of the tcp connection. > > diff --git a/net/slirp.c b/net/slirp.c > > index 451c0fd1ba..b0b03b2bf5 100644 > > --- a/net/slirp.c > > +++ b/net/slirp.c > > @@ -1159,6 +1159,12 @@ static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp) > > "forwarding rule '%s'", config_str); > > return -1; > > } > > + } else if (g_str_has_prefix(p, "unix-per-connection:")) { > > This is rather a mouthful as a parameter name, It seemed a bit long to me too. > and including '-' in the name is undesirable, since we're already > using '-' as a general separator. That's indeed a no-go. > Could it be just 'unix' to match the use of 'unix' in hostfwd ? That would prevent from being able to get the one-unix-connection behavior. Samuel > > + if (slirp_add_unix(s->slirp, &p[20], &server, port) < 0) { > > + error_setg(errp, "Conflicting/invalid host:port in guest " > > + "forwarding rule '%s'", config_str); > > + return -1; > > + } > > } else { > > Error *err = NULL; > > /* > > diff --git a/qemu-options.hx b/qemu-options.hx > > index 5fe9d73eaa..062cd39aa3 100644 > > --- a/qemu-options.hx > > +++ b/qemu-options.hx > > @@ -3553,6 +3553,15 @@ SRST > > # and connect the TCP stream to its stdin/stdout > > |qemu_system| -nic 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321' > > > > + ``guestfwd=[tcp]:server:port-unix-per-connection:path`` > > + With ``unix-per-connection:``, a new connection is opened to the > > + given unix socket per TCP connection made by the guest. The unix socket > > + need not exist at startup time. > > I think the existing docs probably benefit from an update to > better show how the new parmeter is different from what I > would think was already the semantics. > > > + > > + .. parsed-literal:: > > + > > + |qemu_system| -nic user,guestfwd=tcp:10.0.2.100:1234-unix-per-connection:/tmp/socket > > + > > ``-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]`` > > Configure a host TAP network backend with ID id. > > > > > > base-commit: 71f25c75417d31c214ba2cd26b273c114fc99987 > > -- > > 2.55.0 > >